The present invention relates a mass spectrometer. More particularly, it relates to an improved sample injection method and apparatus for a mass spectrometer.
In mass spectrometric apparatus particularly of the type known as a quadrupole mass spectrometer, a number of different approaches have been provided for introducing the sample to be analyzed into the spectrometer. These have included such means as a conduit for introducing a sample of gas, when the substance to be analyzed is a gas. Others include a pyrolyzer in which the substance to be analyzed is coated on to a needle-like structure. The needle structure is rapidly heated to a temperature to pyrolyze the substance thereon, which pyrolyzed substance is then introduced into the spectrometer. The pyrolyzers of the existing apparatus introduce the limitation that the range of the analysis is relatively limited because the pyrolysis technique produces a temperature characteristic which is specific to a limited range of components to be pyrolyzed. A second disadvantage of the previous pyrolysis apparatus is that the molecular beams resulting from the pyrolysis of the substance tends to radiate in all directions from the surface of the carrier with only a small portion of the resulting molecules being directed toward the analyzer apparatus.